Oil tank



OIL TANK Filed April 13, 1945 March 19, 1946.

Patented Mar. 19, 1946 UNITED STAT TENT oFFlcs on TANK- v Donald M.Nelson and Harvey W. Rockwell, Cedar Rapids, Iowa, assignors to LaPlant-Choate Manufacturing Co., Inc., Cedar Rapids, Iowa,

a corporation of Delaware Our invention relates to an oil tankparticularly adapted for hydraulic systems of bulldozers and the like.

One object of the invention is to provide an oil tank, which may bereadily and inexpensively manufactured of heavy sheet metal or sheetsteel, and welded together, and having a ltering and sediment collectingscreen therein which produces an eiiicient separation of undesirableparticles from the oil passing through the screen by imparting. to theoil a swirling action in a swirl chamber of the tank.

Another object is to provide an oil tank having its elements so arrangedthat the oil is discharged for return to the tank below the level of theoil therein to minimize foaming, and the resultant ineiiciency ofoperation of the hydraulic system.

Still another object is to provide a screen which can be readilyremoved, together with the sediment it has collected, for the purpose ofcleaning the screen, the screen being provided with overflow openingsadjacent its top so that oil can continue to flow, even though thescreen is clogged. v

Still another object is to provide a ller tube having a relatively largeopening into the reservoir or tank so that the condition of the oil andits level in the tank may be inspected, a breather cap being providedfor the ller tube to permit air to pass in or out, as the volume of oilchanges, and provided with filtering material to eliminate dirt and dustpassing into the tank when air is drawn into it.

yStill another object is to provide the breather cap with a gauge roddepending therefrom by the use of which the level of the oil can begauged.

Still a further object is to provide a tankparticularly adapted formounting beside the drivers seat of a tractor, and having a depressedpart to receive a control valve in a position Where it is handy for theoperator to operate, the tank also having a bracket adjacent thisdepression to support the valve in alignment with the inlet of the tank.

With these and other objects in View, our invention consists in theconstruction, arrangement and combination of the various parts of ourdevice whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in our claims and illustrated in theaccompanying drawing, in which:

Figure 1 is a plan view of our oil tank, with parts broken away andother parts shown in section;

Figure 2 is a side elevation thereof, also with parts broken away andother parts shown in section, and diagrammatically showing a hydraulicsystem connected therewith; v

Figure 3 is a perspective view of our oil tank showing how it is mountedbeside the drivers seat of the tractor; and

Figure 4 is an end view ofthe oil tank taken from the right-hand end ofFig-ure 2.

On the accompanying drawing we have used the reference numerals I0, I2and I4 to indicate, in general, the bottom, vertical walls and top,respectively, of our oil tank. These parts may be cut to shape fromheavy sheet metal or sheet steel, and suitably welded together to form aliquid-tight compartment. The bottom I0, it will be noted, slopes towarda point adjacent a drain tube I6. rl'his tube may be internallyscrewthreaded to receive an ordinary pipe plug Il (see Fig. 3), whichmay be removed when it is desirable to drain the tank. Because of theslanting bottom, it is necessary to have a level supporting means, andthis is provided in the form of a band of strap steel I8, welded inposition. The top I4 has a slop-ing portion |45, and a part of this iscut away to provide a depression, indicated at 20. The depression 20 isprovided to receive a control valve V, which may be supported on abracket 22 welded to the tank at one side of the depression.

Within the tank is provided a swirl chamber, in the form of a cylinder24.l This is open at the top, and issurrounded by a screen 25. Thescreen 26 may be formed of an outer layer of quarterinch mesh galvanizedhardware cloth and an inner layer of iiner mesh woven brass Wire. Theupper end of the screen is welded or brazed to a supporting nange 28which rests on a shoulder of a bolting flange 3U. rThe bolting flange iswelded to the top I4, and bolted to it by bolts 32 is a breather tubeange 34. A suitable gasket is interposed between the flange 34 and theanges 28 and 30 to effect a seal. The flange 28, above the upper end ofthe screen 2S, is provided with overflow openings 36. This ange is alsoprovided with a lift rod 38 for lifting the screen as sembly out of thetank for cleaning, after the bolts 32 and the flange 34 are removed.

At the bottom of the screen 26 an annular gutter 4l) is provided forcatching sediment, as will hereinafter appear. This gutter slips readilyover the swirl chamber 24. The breather tube flange 34 has extendedupwardly therefrom a filler tube y42,

It is threaded at its upper end so that a breather cap 44 may be screwedthereon.

The breather cap 44 has a bottom plate 46 provided with severalperforations 41 and a breather screen 48. Confined within the screen 48,and

ways 54 extend downwardly therefrom. TheV lower ends of thesepassageways communicate with atmosphere.

Depending from the breather cap 44 is an oil gauge rod 56,1iavingaflange 58 to retain the bottom plate 46 in position, the flange, inturn, being drawn against the plate by an acornnut 'Bil on the upper endof the gauge rod. The gauge rod may have a mark or groove $2 thereon, atthe desired oil level 63. .The ller tube liange 34 is provided with anenlarged opening 64 through which the gauge rod extends into the oiltank.

An oil inlet tube 66 extends from the depression 20 into the swirlchamber 24, entering the swirl chamber at a tangent, as shown inFigure 1. The inlet tube 66 is bent S-shaped within the reservoir, andpasses over a baie plate 68. The baille plate minimizes oil splash inthe tank whenV the tractor is in motion and has four half circleopenings 65 adjacent its lower edge (see Fig. 4).

An outlet pipe l is providedrfor withdrawing oil from the front end ofthe tank. In certain installations the oil may be taken from; the backend of. the tank, and, for this purpose, an auxiliary outlet 12 isprovided. When` one outlet is used, the other one is suitably plugged.

The valve V, supported on the bracket 22, is a four-way valve, as shownin Figure 21, and is ccn-v nected with a hydraulic cylinder C and a pumpP, in addition to being connected to thenlet 65 and the outlet 1G, inthe manner shown. diagrammatically. It is shifted to the right ci thebracket in the diagram to avoid confusion. The. cylinder Cy hasan.operating piston` 7.4 thereinconnectedwith a piston rod 16. whichextends to the bulldozer blade, or other element to be moved by thehydraulic mechanism. The valve V the position shown, locks the pistonagainst movement, and permits the pump to merely circulate the oilthrough the reservoir or tank. This is the idling position.

' To cause the piston i4 to move either to the right or left, the valveV is turned a quarter turn, counter-clockwise, or clockwise,respectively. The desired amount oimovement can be had", and then thepiston again lockedin its new position.

Our tank` structure permits a great volume of oil to ow through thereservoir, with the swirling action produced by tangential dischargeofthe oil into the swirl chamber 24 producing' an eil'cient settlingaction of the foreign material, such' as metal chips, welding spatter,core sand the' like; which may be lodged in the pipe or other parts or'the hydraulic1 system. 4This foreign material is prevented bythe screenfrom passing through the pump and other working parts of' the hydraulicsystem which may be thereby damaged. The swirling action causes theparticles of foreign material to be thrown outward tothe inner surfaceof the screen, where they areltrapped, and mostv oi them eventuallylodge in the gutter-shaped sedi.-Y ment trap 4t.. l

The basket-type screen. is readilyY` removable from the tank withoutthenecessity of' separating a U-shaped annular sediment collecting gutter'the breather cap and oil gauge, these parts being removed in theirentirety as a unit. The screen permits a large quantity of oil tocirculate, and in a tank of a size approximately sixteen inches high, asmuch as fifty gallons a minute can be passed through theA tank withoutoverloading it. AnyV clogging of the screen, however, will not reducethe volume, as overflow can occur through the openings 38.

The oil, it will be noted, enters the tank below the normal oil levelB3, and this minimizes aeration and foaming. Frothing or foaming reducesthe eiiiciency of the system, and our arrangement is such as to increasethe efficiency to a maximum.

Duringoperation of the hydraulic system, the inlet pipe 66, when thevalve is open for operating the piston "M, serves as a return from thecylinder, whereas. during the idling period, it is a direct returnthrough the valve from the outlet side o1' the pump P. The arrangementof the parts of the tank is such that the handle of the valve, indicatedat 13 in Figure 3, is handy to the operator as he drives the tractorfromthe seat 80. The tank itself is supported on a shelf 82 at the side ofthe operators seat.

Some changes may be made in the construction and arrangement of theparts of our device without departing from the real spirit and purposeof our invention, and it is our intention to cover by our claims anymodified forms of structure, or use of mechanical equivalents, which maybe reasonably included within their scope. A

We claim as our invention;

I. In an oil tank of the character described., a reservoir, a vertical.tubular screen depending thereinto and closed at its top, a cylindricalbaiile in the bottom of said screen having its bottom closed and its topopen, said baiile constituting a swirl chamber, an annular U -shapedsediment collecting gutter surrounding said swirl chamber and, togetherwith the swirl chamber, constituting a bottom for said screen, an inletto said reservoir extending t'ang'entially into said swirl chamberr andan outlet from said reservoir beyond said screen.

2. In an oil tank, a reservoir, a Vertical tubular screen therein and'having' a closed top, a cylindrical baille inside said screen having itsbottom closedy and its top open', said bale constituting a swirlchamber, an inlet to said reservoir extending tangentially into saidswirl chamber tocau'se rotation of the oil therein and discharge of theoil from the upper'end of the swirl chamber and'. ra'- dially throughsaid screen, and an outletfrom said reservoir beyond said screen.

3; In an oil tank of the character described, a reservoir, a verticaltubular screen positioned therein with its top closed, a cylindricalbaffle' Within said screen having its bottom closed and its top open,said baille constituting a swivel chamber', ari inlet to said reservoirextending tangentiall'y' intol said swiri chamber, the oil discharging"from the upper' end of the swirl cham'- ber and radially thrusaidscreen,and an outlet from said reservoir beyond said screen.

4. ln an oil tank of the class described, a reservoir, a verticaltubular screen therein, closed at its top and having overflow openings'located at the top of' the screen, a nl'ler-tubeover said screen, acapon said ller tube and havingv a gauge rod extending downwardlytherefrom into' the screen, an openl top cylindrical baille in'` thebottom of said' screen, providing' a swirl chamber,

surrounding said swirl chamber' and: constituting a bottom for saidscreen, in conjunction with said swirl chamber, an inlet to saidreservoir extending tangentially into said swirl chamber, and an outletfrom said reservoir.

5. In an oil tank, a reservoir, a vertical closed top tubular screenhaving a supporting flange, a removable ller tube flange overlying saidsupporting flange, a ller tube thereon, a breather cap on said iillertube, an open top and closed bottom chamber in the bottom of saidscreenconstituting a swirl chamber, an annular dished sediment collectinggutter surrounding said swirl chamber and constituting therewith abottom for said screen, said supporting flange, screen and gutter beingremovable as a unit for cleaning after said ller tube flange is removed,an inlet to said reservoir extending tangentially into said swirlchamber, and an outlet from said reservoir beyond said screen.

6. In an oil tank structure, a reservoir, a iiller tube flange thereon,a ller tube on said flange, a cap on said filler tube and having a gaugerod extending downwardly therefrom into said reservoir, a verticaltubular screen depending from said ilange into said -reserigoir andhaving a closed top, an open top and closed bottom chamber in the bottomof said screen constituting a swirl chamber, an annular sedimentcollecting gutter dished in cross section and surrounding said swirlchamber and constituting therewith a bottom for said screen, an inlet tosaid reservoir extending tangentially into said swirl chamber, and anoutlet from said reservoir beyond said screen.

7. In an oil tank of the class described, a reservoir, a Verticaltubular screen depending thereinto and having a closed top, a fillertube flange on said reservoir above said screen, a filler tube thereon,a breather cap o n said ller tube, an open top and closed bottom chamberin said reservoir adjacent the bottom of said screen constituting aswirl chamber, a U-shaped sediment collecting gutter adjacent said swirlchamber and in conjunction therewith constituting a bottom for saidscreen, said screen and gutter being removable as a unit from saidreservoir, an inlet to said reservoir extending tangentially into saidswirl chamber, and an outlet from said reservoir beyond said screen.

8. In an oil tank structure, a reservoir having a sloping wall providedwith a depression, a bracket for supporting a valve in said depression,a valve supported thereby, a vertical closed top tubular screendepending into said reservoir, a chamber in the bottom of said screen,said chamber being open at its top and closed at its bottom toconstitute a swirl chamber, an annular U-shaped sediment collectinggutter surrounding said swirl chamber and constituting therewith abottom for said screen, an inlet from said valve.

in said depression to said reservoir and extending tangentially intosaid swirl chamber, and an outlet from said reservoir beyond saidscreen.

9. In an oil tank structure, a reservoir having a wall provided with adepression, a bracket for supporting a valve in said depression, a valvesupported thereby, a vertical closed top tubularv screen in saidreservoir, a chamber in said screen, said chamber being open at its topand closed at its bottom to constitute a swirl chamber, a sedimentcollecting gutter adjacent said swirl chamber and within said screen, aninlet from .said valve in said depression to said reservoir and veX-tending tangentially into said swirl chamber, and an outlet from saidreservoir beyond said screen.

10. In an oil tank structure, a reservoir having a sloping wall providedwith a depression, a bracket on one wall of said depression forsupporting a valve in the depression a valve supported thereby, avertical tubular screen and a chamber in said reservoir, said chamberbeing open at its top and closed at its bottom to constitute a swirlchamber, an inlet extending from said valve in said depression and-tangentially into said swirl chamber, and an outlet from said reservoirbeyond said screen.

11. In an oil tank of the class described, a reservoir, a verticaltubular screen therein and having overow openings located at the top ofthe screen, a filler tube ange overlying said supporting flange, a llertube thereon, a breather cap on said :filler tube and having a gauge rodextending downwardly therefrom into the screen, an inlet to saidreservoir and one side of said screen, and an outlet from said reservoirand the other side of said screen.

12. In an oil tank of the character described, a reservoir, a bailleplate therein, a vertical tubular screen in said reservoir on one sideof said baiie plate and having a closed top, a cylindrical balile in thebottom of said screen closed at its bottom to provide a swirl chamber,an annular dished sediment collecting gutter surrounding said swirlchamber and constituting a bottom for said screen in conjunctiontherewith, an inlet to said reservoir extending tangentially into saidswirl chamber, and an outlet from said reservoir extending from saidside of said baie and through that portion of said reservoir on theother side of said baille plate.

DONALD M. NELSON. HARVEY W. ROCKWELL.

